Thanks for the reference to Sredneiranskie iazyki. I've also looked
at the
website. "GLOB", which has been taken from the parenthesis, is the
transliteration from the Aramaic writing system of Pahlavi, where "L"
and
"B" are ambivalent with "R" and "V/W" at best, so it is not to be relied
on
for a phonetic reconstruction. The word in MP is something like /GRAV/
or
/GeRAW/, corresponding normally to modern Persian /gerow/.

There are similar problems (mainly of random or misconceived selection)
with the other attempts at reconstruction, esp. of the numerals. It
would
have to be shown, for instance, by what stages VECH is related to Iranian
PANJ rather than any of the other IE cognates for "5" (inc. Slavic)
-- or,
for that matter, Tk. BESH!

It certainly doesn't help the case that many of the Bulg. words cited
are
obvious loans from New Persian or Arabic via Turkish.

It is of course well known that Iranian vocabulary was borrowed into
Turkic
and Slavic (e.g. BAG/BOG) at a quite early stage, so there's nothing
surprising in principle about finding cognates. Nothing in principle,
either, to preclude the possibility that the original Bulgars were
ethnicaly/genetically Iranians. But to prove it would take a much more
professional investigation, and I doubt if there's the data to support it.